Required backwards support level?

[Michel Dänzer]

On Son, 2014-04-06 at 15:26 +0300, Lauri Kasanen wrote:
> Hi,
> 
> Obviously old userspace + new kernel combo needs to be supported. But
> I'm not so sure about a mixed case, does old userspace + new userspace
> need to be supported to run at the same time?
> 
> For example, a new 64-bit mesa+libdrm and a 32-bit old set, both
> running apps at the same time.
> 
> Or is it acceptable to assume that once a new userspace has been run,
> an old one won't be run for this boot?

I'm afraid not. Trivial counter-example: Build Git snapshot from after
your changes, hit regression (not necessarily related to your changes),
run git bisect involving snapshots from before your changes.


-- 
Earthling Michel Dänzer            |                  http://www.amd.com
Libre software enthusiast          |                Mesa and X developer